ISS till 2028?
Pat Flannery
http://spaceflightnow.com/news/n1003/11station/
...one problem in doing this is that, like Mir, you would then be using
equipment that was never rated for anywhere this long of orbital
lifetime, so you can expect a lot of failures as things wear out.
Pat
Frogwatch
How could you make ISS "upgradable"? After all, it seems a shame to
de-orbit it just when it gets finished and it has yet to accomplish
anything.
David Spain
Keep extending along Truss 1? Close off the inner modules as they become
inhabitable? Like an orbital Scrabble(tm) game.
?
Dave
Pat Flannery
On Mir, the original idea was that the modules could be replaced as they
aged, but that idea was quickly dropped due to budget constraints, and
it still left the problem of what to do as the core module they all
docked to itself aged.
ISS isn't really designed with completely replaceable plug-in modules in
mind, as everything attaches to the core group of manned modules that
form its spine, and you can't start tearing the spine back into pieces
once built.
It is supposed to use replaceable equipment racks inside the shells of
the modules (at least on the US built part), but completely cleaning out
a module and replacing everything in it is going to be a very involved
operation, as well as requiring something bigger than a Progress to
carry up the replacement equipment.
Pat
Pat Flannery
>
> Keep extending along Truss 1? Close off the inner modules as they become
> inhabitable? Like an orbital Scrabble(tm) game.
I don't know if Truss 1 allows that, and there is the problem of
aerodynamic drag to consider; it's designed the way it is so that drag
doesn't throw it out of alignment as it orbits.
Although the idea of a space station that has a abandoned and decaying
"inner city" section to it as it expands into the suburbs has a great
Babylon 5 feel to it. :-D
The old core section will be where the giant yellow worms live:
http://www.anomalist.com/reports/mir.html
...and evolve into... THE GREEN SLIME!:
http://www.youtube.com/watch?v=vKESo2ofEcw
I could swear I saw an old episode of Dr. Who where he fought those same
things, and defeated them by being wittier than they were.
Pat
Greg D. Moore (Strider)
It wouldn't be easy, but I think it's possible you could do it if you really
wanted to.
> ?
>
> Dave
--
Greg Moore
Ask me about lily, an RPI based CMC.
David Spain
>
> Can't be done. You have to worry about CG and moment arms for
> reboost.
>
Yeah I was wondering about that too. You need to keep (which one, Zarya?) at
least the core module that provides propulsion at the CG to keep it on orbit.
Unless you design something that can mate to it on-axis to provide reboost
if it becomes inoperable. Would that be preferred/less-costly than fixing
it?
?
Dave
David Spain
> ...
> modules (at least on the US built part), but completely cleaning out a module
> and replacing everything in it is going to be a very involved operation, as
> well as requiring something bigger than a Progress to carry up the replacement
> equipment.
So, as I mentioned to Fred, adding an on-axis module with a mating adapter to
the exterior core module?
?
Dave
David Spain
> Only Intel never released the MMX for the P6!
>
> OM
Not as a co-pro, but I'm *pretty* sure MMX hardware went into the chip, let me
check...
Yessir, an a new set of instructions which evolved over time and are now known
as SSE4.2 in the Intel Core Microarchitecture*.
I worked extensively with the i860 which was the first Intel chip to include
MMX style hardware directly in the processor.
Dave
Brian Thorn
<ohar...@mindspring.com> wrote:
>How could you make ISS "upgradable"? After all, it seems a shame to
>de-orbit it just when it gets finished and it has yet to accomplish
>anything.
Post-2020, replace the solar panels with solar dynamics for more
power/less drag/reduced need for batteries?
Brian
hal...@aol.com
impact, as the iSS life gets extended?
Espically since LEO is now cluttered with garbage, some from
intentially destroyed satellite killers.....
Pat Flannery
> Post-2020, replace the solar panels with solar dynamics for more
> power/less drag/reduced need for batteries?
They looked into the reflector/heat engine ones at the beginning of the
ISS program (in fact clean back when they were working on Space Station
Freedom), but decided the solar cell arrays were a better choice.
One problem I can see for the reflector type is degradation of the
reflecting surface due to atomic oxygen, UV exposure, and radiation.
The mirrored thermal blankets on Hubble deteriorated badly between the
launch and the first maintenance visit, and a lot of the test materials
on the exterior of the the Long Duration Exposure Facility had
completely vanished by the time it was finally recovered after the
grounding due to the loss of Challenger.
Pat
Greg D. Moore (Strider)
> Has anyone run the numbers as to the likelyhood of a killer debris
> impact, as the iSS life gets extended?
>
No, we were leaving that fear-mongering to you.
> Espically since LEO is now cluttered with garbage, some from
> intentially destroyed satellite killers.....
--
Pat Flannery
> No, we were leaving that fear-mongering to you.
Sooner or later, something is bound to hit something that's manned in
orbit with enough force to punch a hole in it, as there have been lots
of space impacts of smaller sizes on stations and shuttles already.
Although we can maneuver the ISS out of the way of debris we can track,
or known small debris clouds in orbit, the same can't be said for
incoming meteors, and one of those was thought to be the cause of a
satellite loss already:
http://answers.google.com/answers/threadview/id/110401.html
"With regard to the International Space Station, the above article also
points that the ISS "has armor to protect it against stuff as much as
an inch across." So it sounds like the risk to the ISS is pretty
close to zero since meteors are usually much less than an inch across."
I seriously doubt that the ISS is capable of sustaining a hit by a piece
of rock an inch in diameter, as that would be equivalent to hitting it
with a 25mm cannon round going at over 11,000 meters per second.
A Bradley IFV is armed with a 25 mm cannon firing rounds that have a
muzzle velocity of 1,100 meters per second, and those have destroyed
T-72 tanks.
So unless the crew modules of the ISS are covered in several inches
worth of armor plate, a fairly small meteor hit is going to blow a hole
in them.
Pat
Pat Flannery
>
> Maybe someone originally opined or calculated that the ISS can survive a
> fleck of paint as much as an inch across, or that an inch-size rock
> striking a pressurized module would leave a pair of holes small enough
> for the rest of the complex to survive, and the distinction was lost
> during serial retelling. :-)
It would be fun to figure out how much total energy would be released in
a impact like that, assuming the impactor was rock or nickel-iron.
I got my little tektite off the shelf, and that's about an inch in size,
and weighs in at 1/4 ounce, or 110 grains.
Using this bullet impact energy calculator:
http://www.firearmexpertwitness.com/customguns/calcnrg.html and
converting the 11,000 meters per second velocity into 36,080 feet per
second, we end up with a impact force of 317,891.67 foot-pounds.
Ouch.
The small ones that have hit satellites were converted into plasma by
the heat released on impact. The effect internally on the ISS would be
like having a hand grenade going off in the room, due to the severe
shockwave generated by the hypersonic plasma and vaporized metal being
blown out of the impact hole.
Pat
Jorge R. Frank
> "Pat Flannery" <fla...@daktel.com> skrev i meddelelsen
> news:j8OdnRJrvb9jWAHW...@posted.northdakotatelephone...
>
>> "With regard to the International Space Station, the above article also
>> points that the ISS "has armor to protect it against stuff as much as
>> an inch across." So it sounds like the risk to the ISS is pretty
>> close to zero since meteors are usually much less than an inch across."
>>
>> I seriously doubt that the ISS is capable of sustaining a hit by a piece
>> of rock an inch in diameter,
>
>
> Maybe someone originally opined or calculated that the ISS can survive
> for the rest of the complex to survive, and the distinction was lost
> during serial retelling. :-)
Nah, more likely someone confused units. The real limit is 1 cm, not 1 inch.
Anthony Frost
Pat Flannery <fla...@daktel.com> wrote:
> "With regard to the International Space Station, the above article also
> points that the ISS "has armor to protect it against stuff as much as
> an inch across." So it sounds like the risk to the ISS is pretty
> close to zero since meteors are usually much less than an inch across."
>
> I seriously doubt that the ISS is capable of sustaining a hit by a piece
> of rock an inch in diameter, as that would be equivalent to hitting it
> with a 25mm cannon round going at over 11,000 meters per second.
> A Bradley IFV is armed with a 25 mm cannon firing rounds that have a
> muzzle velocity of 1,100 meters per second, and those have destroyed
> T-72 tanks.
> So unless the crew modules of the ISS are covered in several inches
> worth of armor plate, a fairly small meteor hit is going to blow a hole
> in them.
You might well find that it's the lower velocity impacts would cause
most trouble. The high velocity stuff is mostly going to vapourise as it
hits the outer shell of a module and disperse most of the energy in the
insulation before anything reaches the pressure hull, and what does get
through will be spread over a much larger area.
Anthony
Greg D. Moore (Strider)
> In message
>
>
> You might well find that it's the lower velocity impacts would cause
> most trouble. The high velocity stuff is mostly going to vapourise as
> it hits the outer shell of a module and disperse most of the energy
> in the insulation before anything reaches the pressure hull, and what
> does get through will be spread over a much larger area.
Keep in mind too that "outer shell" is a Whipple shield which will
dissappate a lot of the damage.
while trying to remember if it was Whipple or something else, I came across:
http://orbitaldebris.jsc.nasa.gov/protect/shielding.html
>
> Anthony
Peter Cushing's Ghost
NASA seems hell-bent on duplicating every near-disaster MIR had.
Pat Flannery
>> Maybe someone originally opined or calculated that the ISS can survive
>> a fleck of paint as much as an inch across, or that an inch-size rock
>> striking a pressurized module would leave a pair of holes small enough
>> for the rest of the complex to survive, and the distinction was lost
>> during serial retelling. :-)
>
> Nah, more likely someone confused units. The real limit is 1 cm, not 1
> inch.
Even that is going to make one hell of a bang when it hits, if it's
something falling into Earth's gravity well rather than something in orbit.
The one thing you wouldn't want to hit in orbit is part of one of the
Israeli satellites that are launched into retrograde orbits, so your
impact speed could be up to around 36,000 mph.
Pat
Pat Flannery
>> You might well find that it's the lower velocity impacts would cause
>> most trouble. The high velocity stuff is mostly going to vapourise as
>> it hits the outer shell of a module and disperse most of the energy
>> in the insulation before anything reaches the pressure hull, and what
>> does get through will be spread over a much larger area.
>
> Keep in mind too that "outer shell" is a Whipple shield which will
> dissappate a lot of the damage.
>
> while trying to remember if it was Whipple or something else, I came across:
> http://orbitaldebris.jsc.nasa.gov/protect/shielding.html
Good article, I stuck that one in my favorites folder.
The concept reminds me somewhat of the Chobham armor used on modern tanks.
Pat
Pat Flannery
Well, we haven't rammed it with the Shuttle yet. ;-)
Pat
hal...@aol.com
> > NASA seems hell-bent on duplicating every near-disaster MIR had.
>
> Well, we haven't rammed it with the Shuttle yet. ;-)
>
> Pat
no but spacewalking astronauts found a wrench jammed into the station,
it was deformed by impact, lost from mir or something.
it happened to hit a structural part of the station, if it had hit a
few inches away it would of caused a big hole and lost pressure.
call it what you want but its only a matter of time.
and since ISS uses air for cooling a loss of pressure is likely loss
of control. hopefully the astronauts get out safe and sound, but then
we have that big out of control station dropping pieces over its
entire orbital track. almost guaranteed to hit someone or something
important.
as ISS tumbles in uncontrollerd reentry modules will break off
randomly
Transhab would of been a far better design.......
Jeff Findley
"Pat Flannery" <fla...@daktel.com> wrote in message
news:VqOdnd-oH9LggwHW...@posted.northdakotatelephone...
> On 3/13/2010 11:55 AM, Brian Thorn wrote:
>
>> Post-2020, replace the solar panels with solar dynamics for more
>> power/less drag/reduced need for batteries?
>
>
> They looked into the reflector/heat engine ones at the beginning of the
> ISS program (in fact clean back when they were working on Space Station
> Freedom), but decided the solar cell arrays were a better choice.
They were a "better choice" only because they were cheaper to develop. In
the long run, solar arrays require batteries that need periodic replacement
and the solar cells themselves degrade over time.
Solar dynamic power planned on using thermal storage of power, so no
replacement of batteries would be required. Presumably, this would have
been a big "win" in terms of lower maintenance.
> One problem I can see for the reflector type is degradation of the
> reflecting surface due to atomic oxygen, UV exposure, and radiation.
> The mirrored thermal blankets on Hubble deteriorated badly between the
> launch and the first maintenance visit, and a lot of the test materials on
> the exterior of the the Long Duration Exposure Facility had completely
> vanished by the time it was finally recovered after the grounding due to
> the loss of Challenger.
I work with a guy who worked on the optical concentrator design for Freedom.
The reflector degrading over time due to atomic oxygen, ultraviolet
radiation, and micrometeorite impacts was a definite concern.
Jeff
--
"Take heart amid the deepening gloom
that your dog is finally getting enough cheese" - Deteriorata - National
Lampoon